# -*- coding: utf-8 -*-
# -*-coding:utf-8-*-
from time import ctime, sleep
import threading
import numpy as np
import collections


def f1(n, warp):
    print(n)
    warp.append(n)
    return n




if __name__=="__main__":
    arr = []
    for i in range(20):
        x = threading.Thread(target=f1, args=([i, arr]))
        x.start()
        x.join()
        # arr.append(x)
    print(arr)

